/*
 * Copyright (c) MuleSoft, Inc.  All rights reserved.  http://www.mulesoft.com
 * The software in this package is published under the terms of the CPAL v1.0
 * license, a copy of which has been included with this distribution in the
 * LICENSE.txt file.
 */
package org.mule.runtime.config.spring.parsers.assembly;

import java.io.Serializable;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

/**
 * This is used internally by {@link org.mule.runtime.config.spring.parsers.assembly.DefaultBeanAssembler} along with
 * {@link org.mule.runtime.config.spring.parsers.collection.ChildSingletonMapDefinitionParser}. It creates a map with a single
 * key/value pair. This may seem odd, but the result is not manipulated within the assembler - that means that, unlike
 * {@link org.mule.runtime.config.spring.parsers.collection.ChildMapEntryDefinitionParser}, this element can contain nested
 * values. Note that most uses will set
 * {@link org.mule.runtime.config.spring.parsers.assembly.configuration.PropertyConfiguration#isCollection(String)} so that
 * several entries can be combined.
 */
public class MapEntryCombiner implements Map, Serializable {

  public static final String KEY = "key";
  public static final String VALUE = "value";

  private Object key;
  private Object value;
  private Map cachedMerge = new HashMap();
  private boolean isMerged = false;

  private synchronized Map getCachedMerge() {
    if (!isMerged) {
      cachedMerge.put(key, value);
      isMerged = true;
    }
    return cachedMerge;
  }

  public Object getKey() {
    assertNotMerged();
    return key;
  }

  public void setKey(Object key) {
    assertNotMerged();
    this.key = key;
  }

  public Object getValue() {
    assertNotMerged();
    return value;
  }

  public void setValue(Object value) {
    assertNotMerged();
    this.value = value;
  }

  private synchronized void assertNotMerged() {
    if (isMerged) {
      throw new IllegalStateException("Maps have already been merged");
    }
  }

  // map delegates (except hashCode and equals)

  public int size() {
    return getCachedMerge().size();
  }

  public void clear() {
    getCachedMerge().clear();
  }

  public boolean isEmpty() {
    return getCachedMerge().isEmpty();
  }

  public boolean containsKey(Object key) {
    return getCachedMerge().containsKey(key);
  }

  public boolean containsValue(Object value) {
    return getCachedMerge().containsValue(value);
  }

  public Collection values() {
    return getCachedMerge().values();
  }

  public void putAll(Map t) {
    getCachedMerge().putAll(t);
  }

  public Set entrySet() {
    return getCachedMerge().entrySet();
  }

  public Set keySet() {
    return getCachedMerge().keySet();
  }

  public Object get(Object key) {
    return getCachedMerge().get(key);
  }

  public Object remove(Object key) {
    return getCachedMerge().remove(key);
  }

  public Object put(Object key, Object value) {
    return getCachedMerge().put(key, value);
  }

}
